1. Field of Invention
The present invention relates to a pulley structure and a damper pulley. More particularly, the present invention relates to a pulley structure and a damper pulley which are prevented from corroding due to a potential difference.
2. Description of Related Art
In general, a damper pulley is directly fitted on a crankshaft and rotates with it to be able to directly receive torque from the crankshaft that are rotated by an engine. The damper pulley transmits the torque of the engine from the crankshaft to accessories such as a water pump, a power steering system, and an air conditioner.
The damper pulley is formed by combining a hub part, which is fitted on a crankshaft rotated by power from an engine and rotates with it, with a pulley part, which rotates with the hub and is connected with a power transmission member. The hub part and the pulley part may be bolted. When the hub part and the pulley part are bolted, the pulley part that is made of an aluminum alloy or a magnesium alloy and coupling members such as bolts that are made of steel are in contact with each other.
However, when the pulley part made of an aluminum alloy or a magnesium alloy, a side of the hub part made of steel, and the coupling members made of steel are in direction contact with each other, corrosion may be caused by the potential difference between two different metallic materials.
The information disclosed in this Background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.